Wind-measuring meter device



Filed Feb. 11, 1963 JAcK MILLER INVENTOR BY 4m 2 3% A TTORNE) UnitedStates Patent 3,216,247 WIND-MEASURING METER DEVICE Jack V. Miller,Azusa, Calif, 'assignor to Electro-Gptical Systems, Inc., Pasadena,Calif. Filed Feb. 11, 1963, Ser. No. 257,512 5 Claims. (Cl. 73-189) Thepresent invention relates to the metering art for measuring winddirection and the pressures produced by winds upon Vehicles travelingthrough the atmosphere, and more particularly relates to a meteringdevice of the type mentioned that employs electro-optical principles.

Knowledge as to the winds that occur in the lower and upper reaches ofthe earths atmosphere can be important for a number of reasons. Thus,for example, accurate information as to wind direction and intensity isimportant in meteorlogical studies, not only for purely scientificreasons but also, from a practical point of view, for weather controland weather warning purposes. It is also important to have this kind ofinformation in the design and control of high-speed and high-flyingaircraft as well as missiles and rockets. In connection with missile androcket vehicles, for example, the guidance system provides the steeringorders for control of vehicle attitude and trajectory. The controlsystem maintains the proper attitude in the presence of disturbinginfluences. Hence, the design of a guidance and control system requiresan accurate knowledge of the air frame bending modes and residentvibrations likely to be encountered during flight. The instrumentcharacteristics imposed by guidance and control considerations stem fromthe need to detect the disturbing influences with which the guidance andcontrol system must cope. If these disturbing influences can bepredicted from previous flight tests, the control system can be betterdesigned to cope with them. Thus, an accurate knowledge of themagnitude, direction and frequency of these disturbing influences, suchas the winds previously mentioned, will enable the guidance and controlsystem designer to build in the proper lead time for the control system.By so doing, the instant a gust of wind is detected, a signal can besent to the guidance system to begin to generate a steering command tooppose this disturbing influence even before the vehicle itself hasbegun to respond to it. Consequently, a more accurate trajectory can bemaintained for the vehicle.

One of the disadvantages of present-day meter devices of this sort isthat the moving elements in such devices have, relatively speaking, toomuch mass associated with them, with the result that too much inertiahas to be overcome in order to make the system respond quickly to thewind affects. Response time is important because pressure changes in theorder of twenty-five percent per second have been experienced. Inaddition, due to the relatively high masses involved, the frequencyresponse of these meter devices is relatively low, thereby producinginaccuracies in the measurements they make. Furthermore, the movingelements in these earlier devices are mounted on bearings whichinherently involve a certain amount of friction, thereby reducing verygreatly the sensitivity of the instrument. Also, data pick-ofl's fromthese meters are customarily electro-mechanical in nature, usually apotentiometer which, as is well known, includes a wiper element thatmoves along a resistive element. The data pickoff, therefore, adds tothe frictional forces encountered. Friction is important and must beminimized because it reduces the sensitivity of these instruments and,as will be recognized by those skilled in the art, a very high degree ofsensitivity is required at the higher altitudes where the atmosphere isthinnest.

The present invention either eliminates or substantially overcomes theseveral disadvantages mentioned above of ice present day wind meteringinstruments and, in accordance with the basic concept of the presentinvention, this is made possible by using an electro-optical pickolf.More particularly, an embodiment of the invention includes a simple coneor vaned cone that has a two-axes pivot at its tip, the pivot being wellahead of the center of the pressure of the cone, which permits the coneto weather vane into the remote relative wind. A simple and lightweightcone can be fabricated using the electroforming process, a miniaturebellows that acts as a twoaxes flexure pivot being fabricated at thesame time as a part of the conical skirt. Also included in such anembodiment are an extremely lightweight electroformed mirror that isattached to the cone, a light beam source, and a two-axes lateralphotocell type of device. The essence of the operation involvesreflecting the aforesaid light beam off the electroformed mirror andonto the twoaxes lateral photocell device, movement of the cone isresponsive to wind pressures or forces being sensed or determined by thecoordinates of the position of the point of light on the photocellplane.

The electro-optical nature of the present invention makes it possible toprovide a wind-metering instrument that is essentially friction freeabout its operational null. This together with the fact that itencompasses the use of a large surface area of extremely low mass andinertia for wind response and a frictionless pivot point also makes itpossible to provide optimum sensitivity and frequency response in suchan instrument.

Accordingly, it is an object of the present invention to provide awind-metering instrument having great sensitivity and fine frequencyresponse.

it is another object of the present invention to provide a wind-meteringinstrument that substantially eliminates the deleterious effect offriction.

It is a further object of the present invention to provide awind-metering instrument that operates on the basis of electro-opticalprinciples.

It is an additional object of the present invention to provide awind-metering instrument in which parts move relative to each other in asubstantially frictionless manner.

The novel features which are believed to be characteristic of theinvention, both as to its organization and methodof operation, togetherwith further objects and advantages thereof, will be better understoodfrom the following description considered in connection with theaccompanying drawing in which an embodiment of the invention isillustrated by Way of example. It is expressly understood, however, thatthe drawing is for the purpose of illustration and description only andis not intended as a definition of the limits of the invention.

FIGURE 1(a) is a cross-sectional view of a windmetering instrumentconstructed in accordance with the concepts and principles of thepresent invention;

FEGURE 1(1)) is essentially a bottom view of the overall instrument forthe purpose of generally illustrating its form or configuration; and

FIGURE 2 is a cross-sectional view, very greatly enlarged, of theuppermost portion of the instrument shown in FIG. 1(a).

Referring now to the drawings, reference is made to FIG. 1(a) wherein aninstrument constructed in accordance with the present invention is shownto include a hollow conical member 10 at the apex of which is mounted,for protective purposes, a nose cone ll. Manufactured With cone 1'1) asan inherent part thereof is a flexure pivot 32, at the bottom of whichis mechanically attached a mast strut 13. Within the hollow confines ofcone 10 and attached to its sides for support is a mirror device 114-,device 14 preferably being mounted so as to be paral lel to the base ofthe cone and With the mirror surface of this device being on itsbottomside. As shown in the figure, to one side of mirror device 14 isan aperture 14a through which a mast structure 13 extends, the upperpart of the mast structure 14a, that is, that part of it that lies abovethe aperture being the mast strut whereas that part of structure 13 thatlies below aperture 14a is the mast itself which, like cone 10, ishollow and conically shaped. Mast structure 13 is rigidly aflixed at itsbottom to a housing structure 15 which houses the electronic equipmentthat would be used with any embodiment of the present invention, such aspower supplies, amplifiers, etc. Since this is considered standardequipment and, furthermore, since it is not considered pertinent to theinvention, the electronic equipment is not shown. It should bementioned, however, that because mast structure 13 is mounted on housingstructure 15, the mast structure is rigidly held in place, that is tosay, it is immovable. It should also be mentioned at this time inconnection with aperture 14a, through which the mast structure extends,that the aperture is wide enough to permit movement of cone 10 about themast structure, the width of the aperture being determined by the windforces that are expected to be encountered and the restoring forces offlexure pivot 12.

Within the hollow confines of the mast and rigidly mounted to the wallthereof is a light-source arrangement generally designated 16 whichcomprises a lamp 17, a light-converging lens 18, and a mask 19interposed between the lamp and the lens, the mask having a pinhole atits center to provide a point source of light, Also mounted to the wallof the mast at a point where it will received the light reflected frommirror 14 is a radiation tracking transducer 20 whose function it is togenerate a voltage that will vary in amplitude and polarity according tothe position of a spot of light on its surface. A complete descriptionof a radiation tracking transducer of the kind that may be used in theembodiment of the present invention being described may be found onpages 336-341 of an article entiltled Radiation Tracking Transducer byD. Allen, I. Weiman and I. Winslow, in the periodical entitled I. R. E.Transactions on Instrumentation, published in December 1960.

With respect to the manufacture of conical skirt 10, a number ofdifferent techniques are available. One such technique is theelectroforming process previously mentioned, and since this is a wellknown process it is not deemed necessary to describe it in detail here.However, for the purpose of completeness, reference is made to page 2 ofthe patent to Blasius Bart, Patent No. 1,674,941, issued June 26, 1928,wherein may be found an early description of the abovesaidelectroforming process. As was mentioned previously, flexure pivot 12 isan integral part of conical skirt 10 and, therefore, is electroformed atthe same time. Mirror 14 may likewise be fabricated using theelectroforming process. With respect to nose cone or nose tip 11, itprovides a heat sink at the stagna-' tion point. A secondary function ofthis heat sink is to provide a mechanical balance for the cone in orderto locate the cones center of gravity at the center of suppension. Inthis way, angular movements of the cone due to lateral vibrations may beentirely avoided even though the center of suspension of the cone isvery close to the forward end.

The details of flexure pivot 12 is shown in FIG. 2 to which reference isnow made. As is clearly shown therein, the flexure pivot is a bellowsstructure that is a continuation of conical skirt 10. As is also clearlyshown and as was previously mentioned, the flexure pivot, that is tosay, the bellows, is rigidly fastened to the mast strut, this beingaccomplished by bolting the two together by means of bolt 21. Also shownin F162 is nose cone or nose tip 11 which is tightly fastened overconical skirt 1% at its apex. A bottom view of the overall structure forthe purpose of more clearly illustrating its shape is presented in FIG.1(b) In considering its operation, it should first be stated that thespacings between light-source structure 16, radiation trackingtransducer 20, and mirror 14 is such that the converging beam of lightprojected toward the mirror is reflected from its surface to theradiation tracking transducer, the light becoming a point of light bythe time it strikes the transducer surface. Thus, when conical skirt 10is in a neutral position, that is to say, when there are no unbalancedwind forces acting against the conical skirt, the abovesaid point oflight is at the center of the coordinate system on the transducersurface. Consequently, the voltage generated by the transducer is Zero.However, should there be any unbalanced wind forces acting against theconical skirt, then conical skirt 10 will move about flexure pivot 12,the extent of the displacement of the skirt and the direction of itsdisplacement depending upon the magnitude of the forces involved andtheir direction. Since mirror 14 is rigidly fixed to conical skirt 10,any displacement of the conical skirt will produce a correspondingdisplacement of the mirror, with the result that the angle of reflectionof the light beam will also correspondingly change. Ultimately,therefore, the spot of light on the transducer surface will have a newcoordinate position in accordance with the conical skirt displacementand this, in turn, will be measured by the amplitude and polarity of thevoltage generated by the transducer. Although not shown because it isnot deemed significant to the invention, this voltage out of theradiation tracking transducer is fed to the electronics in housingstructure 15 wherein it is amplified and thereafter telemetered back toearth or otherwise used for control purposes.

Having thus described the invention, what is claimed is:

1. A wind-measuring meter comprising: a hollow cone having a bellowsmounted near the apex of the cone in the hollow thereof and integraltherewith; a rigid member positioned within the hollow of said cone andmechanically fixed to said bellows for suspending said cone over andaround said member in a freely swivelable condition; and opticalapparatus positioned within the hollow of said cone and affixed to saidmember for providing a measure of the displacement of said cone from itsbalanced position, said apparatus including an optical detector andmeans for projecting a spot of light onto said optical detector theposition of said spot of light on said optical detector corresponding tothe displacement of said cone from its balanced position.

2. A wind-measuring meter comprising: a hollow cone having a bellowsintegral therewith within the hollow near the apex of said cone; a rigidstrut member positioned within the hollow of said cone and mechanicallyfixed at one end thereof to said bellows for suspending said cone overand around said member in a freely swivelable condition; and opticalapparatus mounted entirely within the hollow of said cone for providinga measure of the displacement of said cone from its balanced position inresponse to wind forces acting thereagainst, said apparatus includingmeans for projecting a converging beam of light, an optical detectorthat produces a voltage whose amplitude and polarity correspond to theposition of a spot of light incident thereon, and a mirror mounted onand moving with said cone for reflecting said beam of light as a spot oflight on said optical detector.

3. A wind-measuring meter comprising: a hollow cone having a bellowsintegral therewith within the hollow near the apex of said cone; amirror rigidly mounted beneath said bellows between the sides of saidcone and movable therewith; a rigidly positioned strut member extendingthrough said mirror and mechanically fixed at one end thereof to saidbellows for suspending said cone over and around said member in a freelyswivelable condition; and optical apparatus mounted within the hollow ofsaid cone and aflixed to said strut member for providing a measure ofthe displacement of said cone from its balanced position in response towind forces acting thereagainst, said apparatus including means forprojecting a converging beam of light against said mirror, and anoptical detector that produces a voltage whose amplitude and polaritycorrespond to the position of a spot of light incident thereon, saidoptical detector being positioned to receive the beam of light reflectedfrom said mirror as a spot of light.

4. The wind-measuring meter defined in claim 3 wherein said opticaldetector is a two axis radiation tracking transducer.

5. A wind-measuring meter comprising: a truncated cone having a flexurepivot at the narrow portion thereof, said flexure pivot being formedintegral with and extending from said cone within the hollow thereof; amirror rigidly mounted between the walls of said cone beneath saidfiexure pivot and facing toward the base of said cone, said mirrorhaving a hole through it; a rigidly positioned strut member extendingthrough said hole and mechanically fixed at one end thereof to saidflexure pivot for suspending said cone over said strut member in afreely movable condition; and optical apparatus mounted within said coneand to said strut member beneath said mirror for providing a measure ofthe displacement of said cone References Cited by the Examiner UNITEDSTATES PATENTS 1,859,020 5/32 Brown 73-432 2,024,571 12/35 Gent 732282,462,577 2/49 Warren 73-489 2,665,583 1/54 Anjanos 73-189 3,034,3485/62 Holderer 73-147 FOREIGN PATENTS 1,093,099 11/60 Germany.

RICHARD C. QUEISSER, Primary Examiner.

JOSEPH P. STRIZAK, Examiner.

1. A WIND-MEASURING METER COMPRISING: A HOLLOW CONE HAVING A BELLOWSMOUNTED NEAR THE APEX OF THE CONE IN THE HOLLOW THEREOF AND INTEGRALTHEREWITH: A RIGID MEMBER POSITIONED WITHIN THE HOLLOW OF SAID CONE ANDMECHANICALLY FIXED TO SAID BELLOWS FOR SUSPENSING SAID CONE OVER ANDAROUND SAID MEMBER IN A FREELY SWIVELABLE CONDITION; AND OPTICALAPPARATUS POSITIONED WITHIN THE HOLLOW OF SAID CONE AN AFFIXED TO SAIDMEMBER FOR PROVIDING A MEASURE OF THE DISPLACEMENT OF SAID CONE FROM ITSBALANCED POSITION, SAID APPARATUS INCLUDING AN OPTICAL DETECTOR ANDMEANS FOR PROJECTING A SPOT OF LIGHT ONTO SAID OPTICAL DETECTOR THEPOSITION OF SAID SPOT OF LIGHT ON SAID OPTICAL DETECTOR CORRESPONDING TOTHE DISPLACEMENT OF SAID CONE FROM ITS BALANCED POSITION.